This invention relates generally to fire suppression systems used in buildings, restaurants and other commercial kitchens, and more particularly, to blow-off caps used on nozzles within the fire suppression systems.
Fire suppression systems provide an integral service to commercial kitchens, which use multiple cooking appliances (e.g. chain broilers, deep fryers, broilers, cook tops, and the like) to cook large quantities of food. The cooking appliances are often operated at high temperatures for extended periods of time, creating a large amount of grease and other effluent.
Fire suppression components are located over the top of the cooking appliances, aimed inside partially enclosed cooking appliances, and are within hoods and ducts associated with the exhaust system. When a hazardous condition is detected, a fire suppression agent is discharged through a nozzle to eliminate the hazardous condition. The fire suppression agent may be, for example, a chemical agent, water, or a combination of the two.
Due to the large amount of effluent present in the location of the nozzles, clogging of the orifice or orifices through which the fire suppression agent is discharged needs to be prevented so that the system activates correctly when needed. A cap is therefore affixed to the nozzle. The cap is to be blown or pushed off the nozzle, or broken or burst, by the pressure created when fire suppression agent is discharged.
A silicone rubber cap has been used to cover the end of the nozzle. However, the rubber cap deteriorates due to effluent build up and the high temperature experienced in the exhaust area over broilers and other cooking units. A brass cap held onto the nozzle with a retaining clip has also been used. The retaining clip weakens over time due to, for example, the extreme temperature gradients, allowing the cap to fall off the nozzle. Also, grease accumulates inside the cap and nozzle, effectively freezing the cap onto the nozzle and/or clogging the orifice.
Therefore, a need exists for a blow-off cap and nozzle assembly capable of withstanding the extreme conditions experienced in commercial kitchen applications, while still allowing the blow-off cap to be pushed off the nozzle during a fire discharge situation. Certain embodiments of the present invention are intended to meet these needs and other objectives that will become apparent from the description and drawings set forth_below.